Manufacture of viscose artificial silk



Patented June 18, 1935 UNlTEDCiSTATES 2,005,664 MANUFACTURE or v soosn ARTIFICIAL Harold Sagar, Whitworth, Emile Van Weyenbcrgh, Rochdale, and Richard Owen Jones,

Manchester,

British company England, assignors to Breda- Visada Limited, Littleborough,

England, a

No Drawing. Application April 6, 1931, Serial No. 528,238. In Great Britain May 9, 1930 8 Claims. (01. 106-40) This invention relates to the preparation of artificial silk of diminished lustre from viscose.

It has already been proposed to produce an artificial silk having a dull finish by incorporating various oils and fats in viscose spinning so lutions. Glycerol esters of fatty acids, however, are particularly susceptible to hydrolysis in the viscose spinning solutions and it is, therefore, only possible to incorporate them a short time before spinning as on standing for some hours in contact with the alkali of the solution, saponification takes place. Hydrocarbon oils have been proposed for incorporation with the viscose for producing an artificial silk of diminished lustre but these tend to separate and/or cream. It is generally necessary therefore with the materials which have been proposed to employ special apparatus to enable the emulsions to be produced or added to the viscose shortly before the spinning process. We have found that esters which are obtained from a hydrogenated phenol and a monoor poly-carboxylic acid are sufficiently resistant to hydrolysis to enable them to be employed without risk of saponification during the period of time in which they may have to be left in contact with the alkali.

According to the present invention, therefore, we produce artificial silk of diminished lustre from viscose by incorporating in the viscose, prior to spinning, a small proportion of a difilcultly hydrolyzable ester of a hydrogenated phenol and a monoor poly-carboxylic acid. Thus the methyl cyclohexanol esters'of cinnamic acid, or of methyl adipic acid, or of fatty acids such as oleic, stearic, palmitic acids or mixtures thereof are suitable. Mixtures of two or more such esters may be used.

The substances used in the present invention give relatively stable emulsions which remain unchanged during filtering or ripening operations. Although they are esters they are surprisingly resistant to saponification by the alkali present in the viscose solutions and thus they may be added in the ordinary apparatus just before spinning either as such or together with an emulsifying agent or as a pre-formed emulsion. They may, however, be added at any earlier stage, for example, in solution in the carbon-disulphide used for xanthating or at any subsequent stage prior to spinning.

This results in a considerable simplification of the process and secures undisturbed working of the plant since the esters can be added at any desired stage in the-existing processes and apparatus. If preformed emulsions are employed they may be produced with the aid of an emulsifying agent.

The amount of ester employed need only be small. 1% or less is sufficient, (i. e. 1% or less of the weight of the whole viscose). Thus the amount may be up to 16% and preferably about 8% of the weight of actual cellulose in the viscose. I

The following examples serve as practical illustrations of the invention, which, however, is in no way limited to the examples.

Example 1 0.3 to 1 part of the ester of methyl adipic acid and methyl cyclohexanol, technically; known as Sipalin M. O. M. is dissolved in the carbon bisulphide which is used to make 100 parts of viscose containing from 7-8 parts of cellulose. The viscose can then be filtered, evacuated and spun in the usual way.

Example 2 0.3 to 1 part of the ester prepared from commercial stearin (which contains such fatty acids as stearic, palmitic, oleic and iso-oleic acids) and cyclohexanol is added to the vessels whilst the cellulose xanthate is being dissolved, in order to form 100 parts of viscose solution. The mixture can then be filtered, evacuated and spun in the usual way.

We declare that what We claim is:-

1. Unripened viscose having emulsified therein a small proportion of a difiicultly hydrolyzable ester of a hydrogenated phenol and a carboxylic acid.

2. Ripened viscose having emulsified therein a small proportion of a difficultly hydrolyzable ester of a hydrogenated phenol and a carboxylic acid.

3. Viscose artificial silk having distributed therein a small proportion of a difficultly hydrolyzable ester of a hydrogenated phenol and a carboxylic acid.

4. Viscose having emulsified therein a small proportion of a difficultly hydrolyzable ester of methyl cyclohexanol and a carboxylic acid.

5. Viscose artificial silk having able ester of methyl cyclohexanol and a carboxylic acid.

6. Viscose artificial silk having distributed therein a small proportion of a difficultlyhydrolyzdistributed thereina small proportion of a diflicultly hydrolyz- 2 t 2,005,664 r t n, ableester oi a hydrogenated phenol and a. therein a small proportion of a, diflicultly hyfatty acid. drolyzable ester of a. methyl cyclohexanol and 7. Viscose having emulsified therein a, small methyl adipic acid. proportion of a difiiculty hydrolyzable ester of a. HAROLD SAGAR. 5 hydrogenated phenol and methyl adipic acid. E. VAN; WEYENBERGH. 5

8. Viscose artificial silk having distributed R. 0..JONES. 

